1. Field of the Invention
The present invention relates to a liquid crystal display (LCD), especially relates to a semi-reflective liquid crystal display module that meets the requirements of high brightness and color under the gray scale and color scale display mode.
2. Description of the Prior Art
It is known that traditional colorful liquid crystal display shows by the usage of the light from its environment under reflective mode, and it shows by the usage of the light provided by the backlight system under transmissive mode, which is named transmissive display.
The structure of known semi-reflective liquid crystal display is shown in FIG. 1, wherein a liquid crystal display 10 includes a top and a bottom glass 12, 12′, which are arranged in a parallel way; between the relative surfaces of the top galss 12 and the bottom glass 12′ are a liquid crystal layer 14, a color filter 16 and a semi-refletcor 18, and a top polarizer 20 and a bottom polarizer 20′ are covered on the outer surface of the top glass 12 and bottom glass 12′ respectively. In addition, a backlight system 22 is set at the back light position of the semi-reflector 18. By turning on the backlight system, makes the backlight transmits through the top polarizer, which is known as transmissive display. While the backlight system is off, the liquid crystal display shows by reflecting the light, which is known as reflective display. The mentioned display styles are the principle of semi-reflective liquid crystal display that has already applied to the display panel of colorful mobile phone.
However, the structure of the liquid crystal display 10 which sets the semi-reflector 18 under the color filter 16 as mentioned causes the high energy loss of the reflected light because light from the outside world is reflected by the semi-reflector 18 when the backlight system 22 is off and the mobile phone is under reflective mode while it is standby, therefore the light has to pass the color filter 16 twice, and the transmittance is limited. And it makes the reflection rate of colorful mobile phone is quite lower than monochrome one which also causes the bad displaying outcome when the colorful mobile phone is standby under dark environment. To raise the reflection rate of colorful displays, known technologies always lower the color selectivity of the color filter 16, however, it always decreases the color gamut on the contrary and cannot give consideration to high reflection rate and color at the same time. Besides, the information users need to know is time, capacity of the battery and the like while the phone is standby, which can be achieved only by the reflective mode of the monochrome display. Due to the bad display, users always have to turn on the transmissive mode and touch off the back light to increase the brightness, which not only shortens the using time of the battery, but also makes frame viewing difficult, therefore it is not user-friendly.
To solve the problem, the invention provides a bi-display mode liquid crystal display according to the defects of the known art, to make the display meet the requirements of high reflection rate and highly colorful presentation.